Fate of Combustion-Derived Carbon Compounds in Urban Soils (Funding: CAP LTER http://caplter.asu.edu/)
Rapid urbanization has increased the abundance of combustion-derived carbon compounds in terrestrial and aquatic ecosystems. Although mechanical and chemical techniques have been created to remove pollutants, high costs of implementation have led to increased interest in microbial bioremediation as a cost-effective and efficient alternative. Soil microorganisms are key players in organic matter decomposition and nutrient turnover, and they have been shown to degrade numerous anthropogenic pollutants. The negative environmental consequences of contaminated sites have stimulated regulation on concentrated point-sources, however, the rise in motor vehicle usage and urban-sprawl development have also turned attention to the impacts of non-point, diffuse pollution that occurs at lower intensities but covers larger areas. Some of the most common urban pollutants, Polycyclic Aromatic Hydrocarbons (PAHs), are formed under incomplete combustion conditions and deposit readily to surfaces in both near and distant ecosystems. Many compounds present in combustion-derived emissions are known to be immunotoxic in high concentrations, but little is known about their distribution and environmental fate in highly populated urban areas.
To address these gaps in our knowledge, we will ask, what is the magnitude, fate, and ecological effect of carbon-based pollution in a low-density, arid urban area? To answer this question, we will: 1) characterize and quantify combustion-derived carbon compounds in soils near roadways across the Phoenix valley, 2) explore the abiotic and biotic fate of PAH and other urban compounds in soils, and 3) assess the importance of microbial community structure in PAH storage and dynamics.